Optical discs are a common type of portable media used in computing systems such as personal computers, laptops and multimedia/game consoles. Different types of data can be stored in a digital format on such discs. For example, the compact disc (CD), digital video/versatile disc (DVD) and Blu-ray® disc (BD) are in common use. The CD has been used for storing audio recordings as well as other data. The DVD has been used for storing larger amounts of data, including broadcast-quality digital video. The BD can store even more data such a high-definition video. Optical discs are widely distributed due to their portability but this can conflict with the desire to control access to the content of the disc.